Zero-order-free meta-holograms in a broadband visible range

来源 :PhotonicsResearch | 被引量 : 0次 | 上传用户:cderfvbgtyhnmj
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
The unwanted zero-order light accompanied by the birth of diffractive optical elements and caused mainly by fabrication errors and wavelength variations is a key factor that deteriorates the performance of diffraction-related optical devices such as holograms, gratings, beam shapers, beam splitters, optical diffusers, and diffractive microlenses. Here, inspired by the unique characteristic of nano-polarizer-based metasurfaces for both positive and negative amplitude modulation of incident light, we propose a general design paradigm to eliminate zero-order diffraction without burdening the metasurface design and fabrication. The experimentally demonstrated meta-hologram, which projects a holographic image with a wide angle of 70°×70° in the far field, presents a very low zero-order intensity (only 0.7% of the total energy of the reconstructed image). More importantly, the zero-order-free meta-hologram has a large tolerance limit for wavelength variations (under a broadband illumination from 520 to 660 nm), which brings important technical advances. The strategy proposed could significantly relieve the fabrication difficulty of metasurfaces and be viable for various diffractive-optics-related applications including holography, laser beam shaping, optical data storage, vortex beam generation, and so on.
其他文献
期刊
To be useful for most scientific and medical applications, compact particle accelerators will require much higher average current than enabled by current architectures. For this purpose, we propose a photonic crystal architecture for a dielectric laser ac
期刊
激光技术涉及工业和科学的许多领域,并成为其重要的一部分,如机械制造和机床制造;电工学和电子学;数据处理和数字控制;光学、精密机械和测量技术;材料科学和加工技术;通讯枝术。对这些领域里新产品和经济加工线的形成,激光枝术给予了新的动力。
期刊
A colored 3D surface reconstruction method which effectively fuses the information of both depth and color image using Microsoft Kinect is proposed and demonstrated by experiment. Kinect depth images are processed with the improved joint-bilateral filter
期刊
报道了一种基于光纤激光器内腔调制的低探测极限折射率传感系统。将基于单模-无芯-单模的全光纤多模干涉结构作为损耗调制器件插入光纤激光器环形腔内,采用激光器内腔调制技术获得了高灵敏度、高信噪比、窄半峰全宽的传感信号,从而实现了低探测极限的折射率测量。系统的折射率探测极限可达7.3×10-7 RIU。该传感系统具有输出稳定、温度交叉敏感小的特点,在高精度生物化学传感、海洋环境监测等领域具有一定的应用潜力
数字式摄影验光仪是一种通过摄影来自动测量人眼屈光度的客观验光系统。介绍了摄影验光原理,用光强的观点描述了眼瞳新月图的形成,分析了眼瞳图像的光强分布,为此建立了眼瞳图像的计算机处理方案,有利于提高自动检测人眼屈光度差的精度。
为求解高光谱图像中各物质的分布及含量,将高光谱分类引入端元提取,提出了一种新的端元提取方法。首先利用虚拟维度评估端元数目;然后引入高光谱分类的思想,通过K-means聚类算法对高光谱图像进行非监督分类,对各类物质进行大致分类;在每类物质中提取出光谱值最大的像元,用这些像元构成端元候选集;最后,依据单形体理论,将高光谱图像的像元点在高维空间中构成单形体,体积最大的单形体的顶点即为端元。模拟和真实高光
从光学多维信息获取器件的小、简洁、易集成化的设计角度出发,对超透镜偏振、相位调控的原理进行分析,基于传输相位和几何相位设计了硅基正交圆偏振光同时聚焦的超透镜(工作波长为800 nm),该器件可同时获取目标的两个正交圆偏振光强度信息。利用x偏振光矩形结构和y偏振光矩形结构的相似性简化设计流程,缩短了设计时间;选择深宽比较小和尺寸容差较大的基元结构,降低了加工工艺要求。使用有限时域差分(FDTD)软件仿真验证了器件的偏振分光和聚焦成像功能,超透镜在数值孔径为0.45时的聚焦效率为56.2%。
本文概要地综述了Bi12SiO20(BSO)晶体的主要物理特性以及近几年来在实时全息术、斑纹干涉计量、光学信息处理等方面的应用和作者的一些实验结果。
期刊
运用ZnS干涉滤光片双稳器件的组合,实现了光学多稳态及三值逻辑门。这种器件具有制作工艺简单、阈值功率低和可室温运转等特点,是进行光计算回路可行性研究的理想元件。